<?php

/**
 * This file is part of the Propel package.
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * @license    MIT License
 */

/**
 * Oracle adapter.
 *
 * @author     David Giffin <david@giffin.org> (Propel)
 * @author     Hans Lellelid <hans@xmpl.org> (Propel)
 * @author     Jon S. Stevens <jon@clearink.com> (Torque)
 * @author     Brett McLaughlin <bmclaugh@algx.net> (Torque)
 * @author     Bill Schneider <bschneider@vecna.com> (Torque)
 * @author     Daniel Rall <dlr@finemaltcoding.com> (Torque)
 * @version    $Revision$
 * @package    propel.runtime.adapter
 */
class DBOracle extends DBAdapter
{
	/**
	 * This method is called after a connection was created to run necessary
	 * post-initialization queries or code.
	 * Removes the charset query and adds the date queries
	 *
	 * @see       parent::initConnection()
	 *
	 * @param     PDO    $con
	 * @param     array  $settings  A $PDO PDO connection instance
	 */
	public function initConnection(PDO $con, array $settings)
	{
		$con->exec("ALTER SESSION SET NLS_DATE_FORMAT='YYYY-MM-DD'");
		$con->exec("ALTER SESSION SET NLS_TIMESTAMP_FORMAT='YYYY-MM-DD HH24:MI:SS'");
		if (isset($settings['queries']) && is_array($settings['queries'])) {
			foreach ($settings['queries'] as $queries) {
				foreach ((array)$queries as $query) {
					$con->exec($query);
				}
			}
		}
	}

	/**
	 * This method is used to ignore case.
	 *
	 * @param     string  $in  The string to transform to upper case.
	 * @return    string  The upper case string.
	 */
	public function toUpperCase($in)
	{
		return "UPPER(" . $in . ")";
	}

	/**
	 * This method is used to ignore case.
	 *
	 * @param     string  $in  The string whose case to ignore.
	 * @return    string  The string in a case that can be ignored.
	 */
	public function ignoreCase($in)
	{
		return "UPPER(" . $in . ")";
	}

	/**
	 * Returns SQL which concatenates the second string to the first.
	 *
	 * @param     string  $s1  String to concatenate.
	 * @param     string  $s2  String to append.
	 *
	 * @return    string
	 */
	public function concatString($s1, $s2)
	{
		return "CONCAT($s1, $s2)";
	}

	/**
	 * Returns SQL which extracts a substring.
	 *
	 * @param     string   $s  String to extract from.
	 * @param     integer  $pos  Offset to start from.
	 * @param     integer  $len  Number of characters to extract.
	 *
	 * @return    string
	 */
	public function subString($s, $pos, $len)
	{
		return "SUBSTR($s, $pos, $len)";
	}

	/**
	 * Returns SQL which calculates the length (in chars) of a string.
	 *
	 * @param     string  $s  String to calculate length of.
	 * @return    string
	 */
	public function strLength($s)
	{
		return "LENGTH($s)";
	}

	/**
	 * @see       DBAdapter::applyLimit()
	 *
	 * @param     string   $sql
	 * @param     integer  $offset
	 * @param     integer  $limit
	 * @param     null|Criteria  $criteria
	 */
	public function applyLimit(&$sql, $offset, $limit, $criteria = null)
	{
		if (BasePeer::needsSelectAliases($criteria)) {
			$crit = clone $criteria;
			$selectSql = $this->createSelectSqlPart($crit, $params, true);
			$sql = $selectSql . substr($sql, strpos($sql, 'FROM') - 1);
		}
		$sql = 'SELECT B.* FROM ('
			. 'SELECT A.*, rownum AS PROPEL_ROWNUM FROM (' . $sql . ') A '
			. ') B WHERE ';

		if ( $offset > 0 ) {
			$sql .= ' B.PROPEL_ROWNUM > ' . $offset;
			if ( $limit > 0 ) {
				$sql .= ' AND B.PROPEL_ROWNUM <= ' . ( $offset + $limit );
			}
		} else {
			$sql .= ' B.PROPEL_ROWNUM <= ' . $limit;
		}
	}

	/**
	 * @return int
	 */
	protected function getIdMethod()
	{
		return DBAdapter::ID_METHOD_SEQUENCE;
	}

	/**
	 * @param     PDO     $con
	 * @param     string  $name
	 *
	 * @throws    PropelException
	 * @return    integer
	 */
	public function getId(PDO $con, $name = null)
	{
		if ($name === null) {
			throw new PropelException("Unable to fetch next sequence ID without sequence name.");
		}

		$stmt = $con->query("SELECT " . $name . ".nextval FROM dual");
		$row = $stmt->fetch(PDO::FETCH_NUM);

		return $row[0];
	}

	/**
	 * @param     string  $seed
	 * @return    string
	 */
	public function random($seed=NULL)
	{
		return 'dbms_random.value';
	}

	/**
	 * Ensures uniqueness of select column names by turning them all into aliases
	 * This is necessary for queries on more than one table when the tables share a column name
	 *
	 * @see http://propel.phpdb.org/trac/ticket/795
	 *
	 * @param     Criteria  $criteria
	 * @return    Criteria  The input, with Select columns replaced by aliases
	 */
	public function turnSelectColumnsToAliases(Criteria $criteria)
	{
		$selectColumns = $criteria->getSelectColumns();
		// clearSelectColumns also clears the aliases, so get them too
		$asColumns = $criteria->getAsColumns();
		$criteria->clearSelectColumns();
		$columnAliases = $asColumns;
		// add the select columns back
		foreach ($selectColumns as $id => $clause) {
			// Generate a unique alias
			$baseAlias = "ORA_COL_ALIAS_".$id;
			$alias = $baseAlias;
			// If it already exists, add a unique suffix
			$i = 0;
			while (isset($columnAliases[$alias])) {
				$i++;
				$alias = $baseAlias . '_' . $i;
			}
			// Add it as an alias
			$criteria->addAsColumn($alias, $clause);
			$columnAliases[$alias] = $clause;
		}
		// Add the aliases back, don't modify them
		foreach ($asColumns as $name => $clause) {
			$criteria->addAsColumn($name, $clause);
		}

		return $criteria;
	}

	/**
	 * @see       DBAdapter::bindValue()
	 * Warning: duplicates logic from OraclePlatform::getColumnBindingPHP().
	 * Any code modification here must be ported there.
	 *
	 * @param     PDOStatement  $stmt
	 * @param     string        $parameter
	 * @param     mixed         $value
	 * @param     ColumnMap     $cMap
	 * @param     null|integer  $position
	 *
	 * @return    boolean
	 */
	public function bindValue(PDOStatement $stmt, $parameter, $value, ColumnMap $cMap, $position = null)
	{
		if ($cMap->isTemporal()) {
			$value = $this->formatTemporalValue($value, $cMap);
		} elseif ($cMap->getType() == PropelColumnTypes::CLOB_EMU) {
			return $stmt->bindParam(':p'.$position, $value, $cMap->getPdoType(), strlen($value));
		} elseif (is_resource($value) && $cMap->isLob()) {
			// we always need to make sure that the stream is rewound, otherwise nothing will
			// get written to database.
			rewind($value);
		}

		return $stmt->bindValue($parameter, $value, $cMap->getPdoType());
	}

	/**
	 * Do Explain Plan for query object or query string
	 *
	 * @param PropelPDO $con propel connection
	 * @param ModelCriteria|string $query query the criteria or the query string
	 * @throws PropelException
	 * @return PDOStatement A PDO statement executed using the connection, ready to be fetched
	 */
	public function doExplainPlan(PropelPDO $con, $query)
	{
		$con->beginTransaction();
		if ($query instanceof ModelCriteria) {
			$params = array();
			$dbMap = Propel::getDatabaseMap($query->getDbName());
			$sql = BasePeer::createSelectSql($query, $params);
		} else {
			$sql = $query;
		}
		// unique id for the query string
		$uniqueId = uniqid('Propel', true);

		$stmt = $con->prepare($this->getExplainPlanQuery($sql, $uniqueId));

		if ($query instanceof ModelCriteria) {
			$this->bindValues($stmt, $params, $dbMap);
		}

		$stmt->execute();
		// explain plan is save in a table, data must be commit
		$con->commit();

		$stmt = $con->prepare($this->getExplainPlanReadQuery($uniqueId));
		$stmt->execute();
		return $stmt;
	}

	/**
	 * Explain Plan compute query getter
	 *
	 * @param string $query query to explain
	 * @param string $uniqueId query unique id
	 */
	public function getExplainPlanQuery($query, $uniqueId)
	{
		return sprintf('EXPLAIN PLAN SET STATEMENT_ID = \'%s\' FOR %s', $uniqueId, $query);
	}

	/**
	 * Explain Plan read query
	 *
	 * @param string $uniqueId
	 * @return string query unique id
	 */
	public function getExplainPlanReadQuery($uniqueId)
	{
		return sprintf('SELECT LEVEL, OPERATION, OPTIONS, COST, CARDINALITY, BYTES
FROM PLAN_TABLE CONNECT BY PRIOR ID = PARENT_ID AND PRIOR STATEMENT_ID = STATEMENT_ID
START WITH ID = 0 AND STATEMENT_ID = \'%s\' ORDER BY ID', $uniqueId);
	}
}
